ISSAQUAH, Wash. — At first glance, the neat rows of houses in Issaquah Highlands seem like those in any other suburb. But look closer, and the differences become clear.

Homes and stores are sandwiched tightly together near a mass transit hub. A newly opened medical center has brought hundreds of jobs to the community. And more than half of the development’s 2,200 acres have been maintained as parks and open space.

Just 30 minutes from Seattle, Issaquah Highlands was initially designed with houses spread out, each on its own five-acre lot. But after the state government passed legislation to encourage the preservation of open land, developers and city planners began to re-think the design. And instead, they built a model for a more sustainable suburb.

“There was a fear that farms and rural spaces and wild lands were being gobbled up," said Issaquah Mayor Ava Frisinger. Adapting new theories in urban planning, she said, “we could do something here that would allow people to be in a more compact development where they could…live, work and play."

And one development within the community has gone even further. The 10-unit zHome townhouse complex is the first carbon neutral development of its kind in the United States, said Brad Liljequist, zHome Project Manager for the city of Issaquah.

“About 40 percent of all CO2 emissions in the country come from buildings. About 40 percent of all raw materials are used in construction,” Liljequist said. “So we were looking at those big picture, ecological footprint components, and basically said, well what would it look like to build a house that takes those impacts as close to zero as possible?"

With features like radiant heating and super-insulated walls, the homes use up to two-thirds less energy than a typical townhouse. Solar energy provides power and collected rainwater is used for laundry and gardening. The townhouses have just been listed for sale at prices ranging from $385,000 to $625,000.

When considering sustainability, the location of the project is as important as the design, said architect Catherine Calvert, who took a recent public tour of the zHome development.

"What I think this project has going for it is its proximity to a major transit center,” said Calvert, with the firm Via Architecture. “I think without that it would be challenging to justify the greenness, or the carbon footprint, of a person living in a place like this."

Project manager Brad Liljequist said he hopes zHome might become a model for an industry that has been slow to adapt sustainable technology.

"You're not going to go buy an old model T, but you may well go buy a 1925 bungalow," Liljequist said. "From a technological standpoint or an efficiency standpoint, that home is not all that different than a brand new home. I think there's a huge amount of opportunity to reduce our major environmental footprint nationally by putting a very concerted focus on building."